The present invention relates to a print server, a print control system and a print control method, particularly to a print server provided with a RIP (Raster Image Processor) function, a print control system including the aforementioned print server and an image forming apparatus provided with the RIP function, and a print control method for the aforementioned print control system.
There has been a widespread use of a printing device (hereinafter referred to as an image forming apparatus) such as a photocopier and MFP (Multi-Function Peripheral). When this image forming apparatus is used for printing, the data in the PDL (Page Description Language) format (hereinafter referred to as PDL data) is received from the client device linked to a network. The PDL data is then rasterized (development in bit-map format) to create raster data and printing is executed based on the raster data.
In a system to which plural image forming apparatuses are connected through a communication network, if the process of creating raster data from PDL data (hereinafter referred to as RIP processing) is performed by each of the image forming apparatuses, each image forming apparatus is required to incorporate, into it, the function that performs the above-mentioned RIP processing (hereinafter referred to as a RIP function), and the image forming apparatus has to be designed in a complicate configuration. To solve this problem, such a system uses a configuration in which the print server provided with the aforementioned RIP function is linked to the communication network, and RIP processing is performed collectively by the print server.
Regarding this system, for example, the Japanese Unexamined Patent Application Publication No. Hei 10-40039 discloses a printing system in which a RIP server for converting the Page Description Language (PDL) into raster image data, and an output engine as a network printer not provided with a RIP section for converting the PDL into raster image data are connected with the network. In this system, when making the output engine perform printing, the host computer outputs the PDL corresponding to the content to be printed to the RIP server, and the RIP server develops the PDL as raster image data, which is transferred to the output engine via the network to perform printing.
However, independently of the performance of the image forming apparatus for performing the operation of printing, the conventional server performs RIP processing by itself, and sends raster data to the image forming apparatus. This arrangement may prevent effective printing from being performed in some cases.
For example, if both the print server and image forming apparatus are provided with the RIP function and the RIP function of the image forming apparatus has a greater processing capacity, it is more effective to allow RIP processing to be performed by the image forming apparatus. According to the conventional method, however, RIP processing is performed on the print server side even in such a case, and raster data is sent to the image forming apparatus. This requires a longer time before the output starts.
Also, when the data transfer speed of the communication network is low, it is more effective to send the PDL data which has a smaller data size. Even in such a case, however, RIP processing is performed on the print server side in the conventional method, and the raster data of a greater size is sent. This requires a longer data transmission time, and takes a longer time before the output starts.
The present invention is intended to solve the aforementioned problems. Accordingly a main object of this invention is to provide a print server, a print control system and a print control method where effective printing can be achieved.